1 files changed, 176 insertions, 0 deletions
diff --git a/tests/src/test_random.c b/tests/src/test_random.c
new file mode 100644
index 0000000..f7247e2
--- /dev/null
+++ b/tests/src/test_random.c
@@ -0,0 +1,176 @@
+/**
+ * @file   test_random.c
+ * @brief  Randomized correctness test for malloc/free.
+ *
+ * Allocates random-sized blocks in TINY, SMALL, and LARGE ranges,
+ * fills them with a deterministic pattern, then verifies the data.
+ * Run with system malloc and LD_PRELOAD — output must match.
+ *
+ * Usage: test_random <seed> <count>
+ */
+
+#include <stdlib.h>
+#include <unistd.h>
+
+#define TINY_MAX 128
+#define SMALL_MAX 1024
+#define LARGE_MAX 8192
+
+static void
+_s_put_str (const char *str)
+{
+  const char *p;
+
+  p = str;
+  while (*p)
+    p++;
+  write (1, str, (size_t)(p - str));
+}
+
+static void
+_s_put_nbr (int n)
+{
+  char buf[12];
+  int i;
+
+  i = (int)sizeof (buf);
+  if (n == 0)
+    buf[--i] = '0';
+  while (n > 0)
+    {
+      buf[--i] = '0' + (n % 10);
+      n /= 10;
+    }
+  write (1, buf + i, (size_t)(sizeof (buf) - i));
+}
+
+static unsigned char
+_s_pattern (int seed, int alloc_index, int byte_index)
+{
+  return ((unsigned char)((seed * 31 + alloc_index * 7 + byte_index) & 0xFF));
+}
+
+static size_t
+_s_rand_range (size_t min, size_t max)
+{
+  return (min + (size_t)rand () % (max - min + 1));
+}
+
+static int
+_s_test_category (const char *label, size_t min, size_t max, int seed,
+                  int base_index, int count)
+{
+  void *blocks[count];
+  size_t sizes[count];
+  unsigned char *data;
+  int fail;
+  int i;
+  int j;
+
+  fail = 0;
+  i = 0;
+  while (i < count)
+    {
+      sizes[i] = _s_rand_range (min, max);
+      blocks[i] = malloc (sizes[i]);
+      if (!blocks[i])
+        {
+          _s_put_str (label);
+          _s_put_str ("[");
+          _s_put_nbr (i);
+          _s_put_str ("]: malloc FAILED\n");
+          fail = 1;
+          i++;
+          continue;
+        }
+      data = (unsigned char *)blocks[i];
+      j = 0;
+      while (j < (int)sizes[i])
+        {
+          data[j] = _s_pattern (seed, base_index + i, j);
+          j++;
+        }
+      i++;
+    }
+  i = 0;
+  while (i < count)
+    {
+      if (!blocks[i])
+        {
+          i++;
+          continue;
+        }
+      data = (unsigned char *)blocks[i];
+      j = 0;
+      while (j < (int)sizes[i])
+        {
+          if (data[j] != _s_pattern (seed, base_index + i, j))
+            {
+              _s_put_str (label);
+              _s_put_str ("[");
+              _s_put_nbr (i);
+              _s_put_str ("]: FAIL at byte ");
+              _s_put_nbr (j);
+              _s_put_str ("\n");
+              fail = 1;
+              break;
+            }
+          j++;
+        }
+      if (j == (int)sizes[i])
+        {
+          _s_put_str (label);
+          _s_put_str ("[");
+          _s_put_nbr (i);
+          _s_put_str ("]: OK (");
+          _s_put_nbr ((int)sizes[i]);
+          _s_put_str (" bytes)\n");
+        }
+      i++;
+    }
+  i = 0;
+  while (i < count)
+    {
+      free (blocks[i]);
+      i++;
+    }
+  return (fail);
+}
+
+static int
+_s_atoi (const char *str)
+{
+  int n;
+
+  n = 0;
+  while (*str)
+    {
+      n = n * 10 + (*str - '0');
+      str++;
+    }
+  return (n);
+}
+
+int
+main (int argc, char **argv)
+{
+  int seed;
+  int count;
+  int fail;
+
+  if (argc != 3)
+    {
+      _s_put_str ("usage: test_random <seed> <count>\n");
+      return (1);
+    }
+  seed = _s_atoi (argv[1]);
+  count = _s_atoi (argv[2]);
+  srand ((unsigned int)seed);
+  fail = 0;
+  fail |= _s_test_category ("TINY", 1, TINY_MAX, seed, 0, count);
+  fail |= _s_test_category ("SMALL", TINY_MAX + 1, SMALL_MAX, seed, count,
+                            count);
+  fail |= _s_test_category ("LARGE", SMALL_MAX + 1, LARGE_MAX, seed, count * 2,
+                            count);
+  return (fail);
+}